Universal Contribution Research Articles

N = 4 $$ \mathcal{N}=4 $$ Super-Yang-Mills on conic space as hologram of STU topological black hole

We construct four-dimensional N=4 super-Yang-Mills theories on a conic sphere with various background R-symmetry gauge fields. We study free energy and supersymmetric Renyi entropy using heat kernel method as well as localization technique. We find that the universal contribution to the partition function in the free field limit is the same as that in the strong coupling limit, which implies that it may be protected by supersymmetry. Based on the fact that, the conic sphere can be conformally mapped to $S^1\times H^3$ and the R-symmetry background fields can be supported by the R-charges of black hole, we propose that the holographic dual of these theories are five-dimensional, supersymmetric STU topological black holes. We demonstrate perfect agreement between N=4 super-Yang-Mills theories in the planar limit and the STU topological black holes.

DERECHOS SOCIALES, PROTECCIÓN DE LA SALUD E INTERPRETACIÓN CONSTITUCIONAL

The article is divided in into two parts. The first part is a critique of some usual conceptualizations of social rights that conceive them as social minimums. In this first part, arguments in favor of different interpretations are established: social rights are embodied in citizenship institutions, which allow for universal and equal access to certain benefits that are essential for human development. The second part of the article seeks to challenge the argument that the right to health care, as enshrined in the Chilean Constitution, requires a healthcare system such as the one of the current legal regime, which combines a private system of individual insurance and a public social insurance system. The purpose of this second part is to show that the best interpretation of the Constitution allows and enables the configuration of a universal social health insurance system funded by universal contributions.

Identifying topological order in the Shastry-Sutherland model via entanglement entropy

It is known that for a topologically ordered state the area law for the entanglement entropy shows a negative universal additive constant contribution, $\ensuremath{-}\ensuremath{\gamma}$, called the topological entanglement entropy. We theoretically study the entanglement entropy of the two-dimensional Shastry-Sutherland quantum antiferromagnet using exact diagonalization on clusters of 16 and 24 spins. By utilizing the Kitaev-Preskill construction [A. Kitaev and J. Preskill, Phys. Rev. Lett. 96, 110404 (2006)] we extract a finite topological term, $\ensuremath{-}\ensuremath{\gamma}$, in the region of bond-strength parameter space corresponding to high geometrical frustration. Thus, we provide strong evidence for the existence of an exotic topologically ordered state and shed light on the nature of this model's strongly frustrated, and long controversial, intermediate phase.

Voice over Internet Protocol (VoIP): The Dynamics of Technology and Regulation

What Voice over Internet Protocol (VoIP) is going to do is start to weaken the foundation of the way we've done things for 100 years...Congress already should be discussing the next telecom bill,” said Federal Communications Commission (FCC) Chairman Michael Powell in February 2004, before the United States Senate. The objective of this thesis is to study how VoIP challenges the incumbent US telecommunications act. The appearance of VoIP comes at a juncture when telecommunications system has already turned into a large-scale, complex system with multiple, competing infrastructures. VoIP, however, greatly augments the nested complexity by affording a technology that enables multiple architectures and business models for delivering the same voice (and often converged voice and data) service, while remaining agnostic to the underlying infrastructure. The VoIP-enabled architectures have very different capabilities and costs from one another. Many do not – or cannot – support social regulations such as emergency 911, wiretapping and disability access. Most exploit the economic arbitrage opportunities by evading access charges and universal service contributions. Added to this is the combination of reduced asset specificity due to VoIP’s layered architecture and a global standard based ubiquitous IP technology that frees the service providers of the need to own the delivery infrastructure, and enables them to offer service from anywhere globally. Such a misalignment – between regulatory obligations and technical capabilities – has the potential to incubate large-scale systemic failures due to lack of coordination between the local optimization focused private markets and the highly compartmentalized public institutions. The case of Communications Assistance for the Law Enforcement Act (CALEA) – also known as the wiretapping act – is taken to study its implications on VoIP. A system dynamics model is used for the analysis. Four policy lessons emerge through the process of

Percolation approach to glassy dynamics with continuously broken ergodicity.

We show that the relaxation dynamics near a glass transition with continuous ergodicity breaking can be endowed with a geometric interpretation based on percolation theory. At the mean-field level this approach is consistent with the mode-coupling theory (MCT) of type-A liquid-glass transitions and allows one to disentangle the universal and nonuniversal contributions to MCT relaxation exponents. Scaling predictions for the time correlation function are successfully tested in the F(12) schematic model and facilitated spin systems on a Bethe lattice. Our approach immediately suggests the extension of MCT scaling laws to finite spatial dimensions and yields predictions for dynamic relaxation exponents below an upper critical dimension of 6.

Holography for N $$ \mathcal{N} $$ = 2* on S 4

We find the gravity dual of $$ \mathcal{N} $$ = 2* super-Yang-Mills theory on S 4 and use holography to calculate the universal contribution to the corresponding S 4 free energy at large N and large ’t Hooft coupling. Our result matches the expression previously computed using supersymmetric localization in the field theory. This match represents a non-trivial precision test of holography in a non-conformal, Euclidean signature setting.

Comments on Rényi entropy in AdS3/CFT2

We extend and refine recent results on Renyi entropy in two-dimensional conformal field theories at large central charge. To do so, we examine the effects of higher spin symmetry and of allowing unequal left and right central charges, at leading and subleading order in large total central charge. The result is a straightforward generalization of previously derived formulae, supported by both gravity and CFT arguments. The preceding statements pertain to CFTs in the ground state, or on a circle at unequal left- and right-moving temperatures. For the case of two short intervals in a CFT ground state, we derive certain universal contributions to Renyi and entanglement entropy from Virasoro primaries of arbitrary scaling weights, to leading and next-to-leading order in the interval size; this result applies to any CFT. When these primaries are higher spin currents, such terms are placed in one-to-one correspondence with terms in the bulk 1-loop determinants for higher spin gauge fields propagating on handlebody geometries.

Mathieu moonshine in four dimensional $ \mathcal{N} $ = 1 theories

We show that the recently discovered Mathieu moonshine plays a role for certain four dimensional theories with $\mathcal{N}=1$ supersymmetry. These theories are obtained from the $E_8 \times E_8$ heterotic string theory by compactifying on toroidal orbifolds. We find that a universal contribution to the holomorphic gauge kinetic function can be expanded in such a way that the expansion coefficients are the dimensions of representations of the Mathieu group M$_{24}$.

Mutual information after a local quench in conformal field theory

We compute the entanglement entropy and mutual information for two disjoint intervals in two-dimensional conformal field theories as a function of time after a local quench, using the replica trick and boundary conformal field theory. We obtain explicit formulae for the universal contributions, which are leading in the regimes of, for example, close or well-separated intervals of fixed length. The results are largely consistent with the quasiparticle picture, in which entanglement above that present in the ground state is carried by pairs of entangled, freely propagating excitations. We also calculate the mutual information for two disjoint intervals in a proposed holographic local quench, whose holographic energy-momentum tensor matches the conformal field theory one. We find that the holographic mutual information shows qualitative differences from the conformal field theory results and we discuss possible interpretations of this.

Universal Aspects of Ultrafast Optical Pulse Scattering by a Nanoscale Asperity

We combine photoemission electron microscopy and electromagnetic simulations to describe the surface plasmon polariton dynamics following interaction of an ultrafast optical pulse with a slit coupling structure in a silver film. Through analysis of interference phenomena that lead to photoelectron emission from the silver film, we establish the universal contributions of a nanoscale asperity to the scattered surface field. Our results reveal the important role of surface cylindrical waves within the slit in the excitation of surface plasmon.

Isospin breaking in the phases of the K e4 form factors

Isospin breaking in the K ℓ4 form factors induced by the difference between charged and neutral pion masses is studied. Starting from suitably subtracted dispersion representations, the form factors are constructed in an iterative way up to two loops in the low-energy expansion by implementing analyticity, crossing, and unitarity due to two-meson intermediate states. Analytical expressions for the phases of the two-loop form factors of the K ±→π + π − e ± ν e channel are given, allowing one to connect the difference of form-factor phase shifts measured experimentally (out of the isospin limit) and the difference of S- and P-wave ππ phase shifts studied theoretically (in the isospin limit). The isospin-breaking correction consists of the sum of a universal part, involving only ππ rescattering, and a process-dependent contribution, involving the form factors in the coupled channels. The dependence on the two S-wave scattering lengths $a_{0}^{0}$ and $a_{0}^{2}$ in the isospin limit is worked out in a general way, in contrast to previous analyses based on one-loop chiral perturbation theory. The latter is used only to assess the subtraction constants involved in the dispersive approach. The two-loop universal and process-dependent contributions are estimated and cancel partially to yield an isospin-breaking correction close to the one-loop case. The recent results on the phases of K ±→π + π − e ± ν e form factors obtained by the NA48/2 collaboration at the CERN SPS are reanalysed including this isospin-breaking correction to extract values for the scattering lengths $a_{0}^{0}$ and $a_{0}^{2}$ , as well as for low-energy constants and order parameters of two-flavour χPT.

Observations on entanglement entropy in massive QFT’s

We identify various universal contributions to the entanglement entropy for massive free fields. As well as the `area' terms found in [1], we find other geometric contributions of the form discussed in [2]. We also compute analogous contributions for a strongly coupled field theory using the AdS/CFT correspondence. In this case, we find the results for strong and weak coupling do not agree.

Elasticpp¯scattering amplitude at 1.8 TeV and determination of total cross section

The data on $\mathrm{p}\overline{\mathrm{p}}$ elastic scattering at 1.8 and 1.96 TeV are analyzed in terms of real and imaginary amplitudes, in a treatment with high accuracy, covering the whole $t$ range, and satisfying the expectation of dispersion relation for amplitudes and for slopes. A method is introduced for the determination of the total cross section and the other forward scattering parameters and to check compatibility of E-710, CDF, and the recent D0 data. Slopes ${B}_{R}$ and ${B}_{I}$ of the real and imaginary amplitudes, treated as independent quantities, influence the amplitudes in the whole $t$ range and are important for the determination of the total cross section. The amplitudes are fully constructed, and a prediction is made of a marked dip in $d\ensuremath{\sigma}/dt$ in the $|t|$ range $3--5\text{ }\text{ }{\mathrm{GeV}}^{2}$ due to the universal contribution of the process of three-gluon exchange.

Hints of R-parity violation in B decays into τν

In this article we show that the recently observed enhanced semi-leptonic and leptonic decay rates of the B meson into \tau \nu modes can be explained within the frame work of R-parity violating (RPV) MSSM. In particular, RPV contributions involving the exchange of right-handed down-type squarks give a universal contribution to the B+ --> \tau \nu, B --> D \tau \nu and the B --> D* \tau \nu decays. We find that the masses and couplings that explain the enhanced B decay rates are phenomelogically viable and the squarks can possibly be observed at the LHC.

Universal Broadening of the Bardeen-Cooper-Schrieffer Coherence Peak of Disordered Superconducting Films

In disordered superconductors, the local pairing field fluctuates in space, leading to the smearing of the BCS peak in the density of states and the appearance of the subgap tail states. We analyze the universal mesoscopic contributions to these effects and show that they are enhanced by the Coulomb repulsion. In the vicinity of the quantum critical point, where superconductivity is suppressed by the "fermionic mechanism," strong smearing of the peak due to mesoscopic fluctuations is predicted.

Universal contributions to scalar masses from five dimensional supergravity

Abstract We compute the effective Kahler potential for matter fields in warped compactifications, starting from five dimensional gauged supergravity, as a function of the matter fields localization. We show that truncation to zero modes is inconsistent and the tree-level exchange of the massive gravitational multiplet is needed for consistency of the four-dimensional theory. In addition to the standard Kahler coming from dimensional reduction, we find the quartic correction coming from integrating out the gravity multiplet. We apply our result to the computation of scalar masses, by assuming that the SUSY breaking field is a bulk hypermultiplet. In the limit of extreme opposite localization of the matter and the spurion fields, we find zero scalar masses, consistent with sequestering arguments. Surprisingly enough, for all the other cases the scalar masses are tachyonic. This suggests the holographic interpretation that a CFT sector always generates operators contributing in a tachyonic way to scalar masses. Viability of warped supersymmetric compactifications necessarily asks then for additional contributions. We discuss the case of additional bulk vector multiplets with mixed boundary conditions, which is a particularly simple and attractive way to generate large positive scalar masses. We show that in this case successful fermion mass matrices implies highly degenerate scalar masses for the first two generations of squarks and sleptons.

Entanglement entropy for singular surfaces

We study entanglement entropy for regions with a singular boundary in higher dimensions using the AdS/CFT correspondence and find that various singularities make new universal contributions. When the boundary CFT has an even spacetime dimension, we find that the entanglement entropy of a conical surface contains a term quadratic in the logarithm of the UV cut-off. In four dimensions, the coefficient of this contribution is proportional to the central charge 'c'. A conical singularity in an odd number of spacetime dimensions contributes a term proportional to the logarithm of the UV cut-off. We also study the entanglement entropy for various boundary surfaces with extended singularities. In these cases, similar universal terms may appear depending on the dimension and curvature of the singular locus.

Why is inclusive education important to my country?

This article presents a collection of personal perspectives of three academics and one ministry official from various countries in the Asia-Pacific region, namely, New Zealand, Hong Kong, Malaysia, and Thailand, on the importance of inclusive education. These perspectives offer an insider's understanding of the universal and country-specific contributions of inclusive education, as well as their individual visions for the future of their countries. Although discernibly different in terms of the issues raised by the authors specific to their individual countries, these perspectives, nonetheless, echo and announce the same hope and call – to build a better and more inclusive future for all in society.

The Lorentz-invariant boundary action of the confining string and its universal contribution to the inter-quark potential

We study the boundary contribution to the low energy effective action of the open string describing the confining flux tube in gauge theories. The form of the boundary terms is strongly constrained by the requirement of Lorentz symmetry, which is spontaneously broken by the formation of a long confining flux tube in the vacuum. Writing the boundary action as an expansion in the derivatives of the Nambu-Goldstone modes describing the transverse fluctuations of the string, we single out and put in a closed form the first few Lorentz invariant boundary terms. We also evaluate the leading deviation from the Nambu-Goto string produced by the boundary action on the vacuum expectation value of the Wilson loop and we test this prediction in the 3d Ising gauge model. Our simulation attains a level of precision which is sufficient to test the contribution of this term.

Fitting dwarf galaxy rotation curves with conformal gravity

We continue our study of the application of the conformal gravity theory to galactic rotation curves. Previously we had studied a varied 111 spiral galaxy sample consisting of high surface brightness galaxies, low surface brightness galaxies and dwarf galaxies. With no free parameters other than galactic mass to light ratios, we had found that the theory is able to account for the systematics that is observed in the entire set of galactic rotation curves without the need for any dark matter whatsoever. In the present paper we extend our study to incorporate a further 27 galaxies of which 25 are dwarf galaxies and provide updated studies of 3 additional galaxies that had been in the original sample, and again without dark matter find fully acceptable fits, save only for just a few galaxies that we find to be somewhat troublesome. Our current study brings to 138 the number of rotation curves of galaxies that have been accounted for by the conformal gravity theory. Since one of the primary ingredients in the theory is a universal contribution to galactic motions coming from matter exterior to the galaxies, and thus independent of them, our study reinforces one of the central concepts of the conformal gravity studies, namely that invoking dark matter should be viewed as being nothing more than an attempt to describe global physics contributions in purely local galactic terms.